Boiler



Nov. 24, 1936. G. J. LEUVELINK BOILER 2 Sheets-Sheet '1 Filed Jan. 31,1936 INVENTOR ATTORNEYj Nov. 24, 1936. G. .1. LEUVELINK BOILER 1936 2Sheets-Sheet 2 Filed Jan. 31

ATTORNEYS Patented Nov. 24, 1936 BOILER George J. Leuvelink, Buffalo, N.Y., assignor of one-half to John Bos, Buflalo, N. Y.

Application January 31, 1936, Serial No. 61,769

3 Claims. (01. 122174) This invention relates to a boiler which may beused either for heating water or generating steam for household purposesand which is principally constructed of sheet steel or boiler plate.

One of the objects of this invention is to produce a boiler of thischaracter whereby a greater heating capacity is obtained in proportionto the amount of space which is occupied and the quantity of fuel whichis consumed, thereby rendering the boiler particularly well suited forheating houses in which only a comparatively small space is availablefor installing the heating plant.

Another object of this invention is to so construct and arrange theinner and outer shells of the boiler body and water tubes and fire tubesthat the same are strong and durable, also present the maximum heatingsurface and cause a constant circulation of water in the boiler so thatthe water is heated and steam generated rapidly.

A further object of this invention is to provide improved baflie meansfor deflecting the hot gases in the fire box and causing the same tocontact with a greater area of the water tubes whereby the efficiency ofthe boiler is increased and the fuel is utilized to greater advantageand more economically.

An additional object of this invention is to provide simple and emcientmeans for automatically cutting off the suction of the chimney from theboiler when the pressure of the fuel in the fire box ceases and thusavoids cooling the boiler.

A still further object of this invention is to provide improved meansfor indirectly heating water for domestic and other purposes by heatderived from the water which is heated directly in the boiler.

In the accompanying drawings:

Fig. 1 is a front elevation of a boiler embodying my improvements.

Fig. 2 is a vertical longitudinal section of the same, taken on line2--2, Fig. 1.

Figs. 3 and 4 are vertical transverse sections taken on thecorrespondingly numbered lines in Fig. 2.

Fig. 5 is a horizontal section, taken on line 55, Fig. 2.

Fig. 6 is a fragmentary vertical section, taken on line 66, Fig. 4.

In the following description similar characters of reference indicatelike parts in the several figures of the drawings.

The body of this boiler includes an outer shell and an inner shell bothof which are constructed mainly of sheets of steel which are cut to therequired shape and connected with each other by welding so that the samepractically forms an integral structure.

The outer shell comprises a sheet of steel or metal plate which is bentto form two upright longitudinal outer side walls l0, l and a transverseouter top I l which curves upwardly and. connects the upper ends of theside walls. The main part of the outer shell is completed by uprighttransverse inner walls l2, 13 which are made of sheet or plate steel andconnected at their side and top edges, respectively, with the front andrear edges of the side walls I0 and top H l by electric or gas heatwelding.

The inner shell comprises two flat sheets or plates or inner side wallsM of steel or like metal arranged upright and lengthwise along the innerside of the outer side walls IE! but spaced therefrom so as to formtherebetween upright side water legs l which are filled with waterduring normal operation of the boiler. Arranged along the inner sides ofthe transverse outer walls are two transverse inner walls l6, ll formedfrom fiat inner plates or sheets of steel which are spaced from saidouter transverse walls l2, l3 and produce therebetween upright front andrear water legs i8, i9 which are filled with water during use of theboiler. The opposite vertical edges of the inner transverse walls l6 and[1 are connected by welding with the corresponding front and rearvertical edges of the side walls I4. Above the inner side and transversewalls is arranged an inner top 20 of sheet steel or metal which isconnected at its longitudinal and transverse edges with the respectiveupper edges of the inner side and end walls by welding.

This inner top 20 spaced from the outer top H and in the preferred formis transversely bent or corrugated so that one part thereof is off-setvertically relatively to another in a direction lengthwise of the boilerfor the purpose of strengthening the same and enabling it to withstandthe pressure to which the same is subjected. The off-setting orcorrugating is preferably effected by bending the top 20 sothat thefront part 28 of the same is elevated, the rear part 22 depressed, andthe intermediate part 23 inclined downwardly from the front part 2! tothe rear part, as best shown in Fig. 2.

A mud ring or filler closes the water legs between the inner and outershells of the boiler body which ring comprises two side bar sections 24arranged between the lower edge portions of the side walls l0, Mrespectively, and two end bar sections 25 arranged between thecorresponding lower edge portions of the transverse end walls of theshells and said walls and mud ring sections being connected by welding.

The water to be heated may be introduced into the water space betweenthe inner and outer shells of the body in any suitable manner, forexample, through one or more feed pipes 26 connected with the lower rearpart of the rear transverse wall i 3 of the outer shell, as shown inFig. 2, which pipes may also be used as water return pipes when thisboiler is used in a hot water building heating system. The steam or hotwater may be conducted from the interior of the body to the radiators ofthe building or other place where the heat is to be used by pipes 21, 28connected with the top H of the outer shell which piping may beorganized to either return to the boiling water which has been utilizedfor heating in a hot water heating system, or to return the water ofcondensation to the boiler in case the boiler is used for generating andheating by steam.

The top 23 of the inner shell may be provided with a fusible plug 253which is adapted to melt and let off steam in case the water in theboiler gets below the top of the inner shell and thus relieves thepressure in the boiler for safety.

In order to prevent the upper parts of the transverse end walls it, I3of the outer shell from being pressed outwardly by the internal pressureof the steam within the boiler body these parts are connected bylongitudinal tie rod or brace 3e arranged above the top plate of theinner shell, as best shown in Fig. 2. The upper parts of the front wallit of the outer shell are also provided with outlets Si, 32 forconnection with pressure and water gages of usual construction.

Ihe body of the boiler may be supported in any suitable manner but thisis preferably accomplished in the present case by means of a hollow basehaving an outer rectangular casing 33 of sheet metal, such as steel,which. rests on a foundation and is provided at its upper end with aninternal angle iron 34 forming a shoulder upon which the mud ring at thelower marginal part of the boiler body rests, as shown in Figs. 1-4.

The space within the inner shell of the boiler body and the space withinthe base together form a fire box in which the heat is generated forheating the water in the water space of the boiler.

Although the means for heating the water may be organized for utilizingvarious kinds of fuels the present installation purposes the use of fueloil and for this purpose the inner side and bottom of the base isprovided with a refractory lining, as shown by dotted lines 35 in Figs.2, 3, and 4 and a fuel oil burner is provided, as shown by dotted lines36 in Fig. 2, whereby fuel oil and air is projected in the form of acombustible mixture into the lower part of the fire box and burned as aflame in the latter. Part of the heat resulting from the burning of thefuel in the fire box acts upon the inner shell of the boiler body andeffects heating of the water in the space between the inner and outershells of the body.

For the purpose of increasing the area of the surface which is contactedby the hot gases and produce the greatest transference of heat to thewater before these gases escape to the chimney leading to the outeratmosphere additional radiating means are provided which embody somefeatures of the present improvement and which are constructed asfollows:-

The numeral 3! represents a plurality of water tubes which are arrangedlengthwise and side by side in a transverse row in the upper part of thefire box so as to be exposed to the hot gases therein and each of thesetubes inclining from its front end toward its rear end. Each of thesewater tubes is of oval form in cross section and so arranged that theopposite Wide areas or walls thereof are arranged vertically, therebyenabling a large number of water tubes of extensive area to be employedin a given space. Each of the water tubes is provided on its oppositeupright sides with a plurality of longitudinal corrugations 38 arrangedin vertical rows, thereby increasing the strength of these tubes andalso increasing the radiating area of the same. At its front and rearends each of the water tubes extends through correspondingly shapedopenings in the front and rear transverse Walls of the inner shell andis integrally connected therewith by welding.

Within each water tube is arranged a longitudinal rearwardly inclinedfire tube 39 which is of smaller diameter so as to form a water space 40between these tubes which communicates at its opposite ends with thefront and rear transverse water legs l8, l9 and in which Water in theform of a comparatively thin film is exposed to the heating effect ofthe hot gases and thus utilize the fuel more advantageously. Each of thefire tubes is of oval form in cross section and arranged with its widesides vertically and each of these vertical sides is provided withlongitudinal corrugations M which are arranged in a vertical row andthus increase the strength of this tube and also the area of itsradiation surface so as to facilitate the heating of the water in thespace between the respective outer water and inner fire tubes.

At its opposite ends each of the fire tubes eX- tends throughcorrespondingly shaped openings in the front and rear transverse wallsof the outer shell and is secured to the same by welding. By

inclining both the water tubes and the fire tubes a more rapidcirculation of the water in the boiler is obtained.

Extending across the water space of the front water leg l8 below thewater and fire tubes is a transfer flue 42 which communicates with thefire box and which has its inner end formed integrally with the fronttransverse wall I6 of the inner shell and has its front end connectedwith the front transverse wall l2 of the outer shell by welding.

On the front side of the boiler is arranged a flame chamber 43 forconnecting the flue 42 with the front ends of the fire tubes 39 whichchamber preferably comprises a marginal flange 44 connected at its rearedge by bolts 45 with the-front wall l2 of the outer body shell and aclean-out door 4.5 movably mounted on the front side of said flamechamber. Normally this door is closed so that the flame chamber onlycommunicates with the tranfer flue and the fire tubes but when this dooris opened the fire tubes are accessible at their front ends forrepairing, cleaning or inspection.

In rear of the boiler is arranged a smoke box 4'! which communicateswith the rear ends of the fire tubes and is provided at its top with anoutlet flue 48 adapted to be connected with the chimney of the buildingin which the boiler is installed so as to conduct the spent heatinggases and smoke to the outer atmosphere. This smoke box is pro- Videdwith a marginal flange 49 which is secured by bolts 50 to the rear endwall l3 of the outer shell and the rear side of this smoke box isprovided with a movable door 5| which may be opened when access isrequired at the rear ends of the fire tubes for inspection, cleaning orrepairing purposes.

I The hot gases resulting from the burning of the fuel in the lower partof the fire box pass upwardly in the fire box and around the watertubes, thence forwardly through the transfer flue 42, thence upwardlythrough the flame chamber 43, thence rearwardly through the fire tubesand into the smoke box, and thence upwardly through the outlet flue 48to the chimney, thereby heating the water lying against the exposedsurfaces which are contacted by the hot gases for either heating thewater at a relatively low temperature or at a higher temperature ifsteam is desired.

By inclining the water tubes and fire tubes from their front ends towardtheir rear ends the flow of hot gases through the fire tubes is retardedand a greater amount of heat is transferred to the water before thegases escape to the smoke box.

Baifling or deflecting means are provided for preventing the hot gasesfrom passing directly from the lower part of the fire box to thetransfer flue and instead compelling these gases to first pass upwardlyin the fire box and around the rear parts of the water tubes, thencedownwardly around the front parts of the water tubes and then to thetransfer flue and thus obtaining a more extended contact of the hotgases with the water tubes and increasing the efficiency of the boilerfor the amount of fuel consumed.

These baflle means preferably comprise a bafile plate having arearwardly inclined main part 52 extending across the inner end of thetransfer flue 42, a pair of supporting tongues or lugs 53 projectingdownwardly from the lower edge of this main part and removably seated insockets 54 arranged on the inner side of the front Wall of the innershell below the transfer flue 42, and an upright plate portion 55projecting upwardly from the upper edge of the main part 52 andtransversely across the lower part of the water tubes 31 and provided inits upper edge with a plurality of notches 56 each of which receives thelower part of one of said water tubes between the front and rear ends ofthe same.

It follows from this form of bafile that the latter causes the hot gasesrising from the lower part of the fire box to first pass upwardly aroundtherear parts of the water tubes and then over the top of the baffle anddownwardly around the frontparts of the water tubes to the transferflue, thus lengthening the path of the hot gases and retaining the samefor a longer time in contact with the: Water tubes and increasing theheating effect on. the water accordingly.

Strengthening of the longitudinal side walls of the inner and outershells is effected by means of reinforcing tubes 51 each of which isformed integrally at its inner end with the respective innerside wall I4and connected at its outer end with. the companion outer side Wall 10 bywelding, as best shown in Fig. 3. Normally each of these reinforcingtubes is closed by a cover plate 58 extending across the outer end ofthe reinforcing tube and engaging the outer side of the respective sidewall 10, a conical plug 59 fitting the conical. inner end part of thisreinforcing tube, and abolt 60 detachably connecting said plate 58 and.plug 59. When these reinforcing tubes are open the same may be utilizedfor cleaning, repairing and inspecting the adjacent internal parts ofthe boiler. Reinforcing of the side Walls of the innerand outer shellsmay also be effected by stay bolts- 6l connecting these parts, as shownin Figs. 3, 4 and 5.

For the purpose of readily gaining access tothe interior of the fire boxa manhole 62 having the form of a tube is extended across the waterspacebetween one pair of outer and inner side walls of the outer and innershells, which tube is formed integrally at its inner end with therespective inner side wall l4 and connected by welding at its outer endwith the respective outer side wall In, as best shown on the left sideof Fig. 3. The manhole is normally closed by a movable door 63 mountedon the adjacent wall it and this door is provided with a window 64 topermit of observing the burning operation within the fire box. Thistubular manhole also reinforces the side walls on this side of theboiler and stay bolts are not needed.

Means are provided for automatically checking the draft through theboiler when the generation of heat in the fire box ceases or ismaterially reduced and thus prevents cooling of the Water in the boilerat such times. The preferred means for this purpose comprise a checkpassage 65 formed in the upper inclined part 56 of the rear wall of thesmoke box between the clean-out door 5! and the smoke outlet 48, and anunbalanced check valve 61 of the butterfly type adapted to open andclosesaid check passage and pivotally mounted about midway of its lengthon the smoke box so that the same is normally moved into a closedposition by gravity in which it is parallel with the plane of the checkpassage, but when the pressure in the smoke box ceases, due to stoppingor slowing down of the burner, then the suction of the chimney isconcentrated on the check valve and causes the same to be turned into anopen position in which it stands at right angles to the plane of thecheck passage so that air is now drawn from the exterior of the boilerinstead of through the fire box and fire tubes and cooling the water.The unbalanced condition of the check valve is preferably effected bymeans of pivot pins or pintles 68 arranged at the upper lower edges ofthe check valve and in a slightly inclined position relative to avertical line and v.lournalling these pins in correspondingly inclinedbearings 59 on the smoke box, as shown in Figs. 12 and 5. When the heatgenerating means in the :fire box are in operation, particularly an oilburner supplying air under pressure, then the de- :mands of the suctionof the chimney are supplied by this burner and only a slight suctioneffect is produced on the check valve which is sufilcient to permit thesame to remain in a closed position and thereby prevent the entrance ofair in any .substantial amount from the atmosphere through the checkpassage and into the chimney and thus maintain a good draft on the firebox. The move- :ment of the check valve upon reaching its closedposition is arrested by stop means consisting preferably of stop lugs 19arranged at opposite ends of the check valve and adapted to engage withadjacent parts of the smoke box.

When the pressure in the fire box is materially :reduced or arrested andno longer supplies the demands of the suction of the chimney then thecontinuance of the strong suction in the latter will be exerted moreeffectively on the check valve and cause the same to be turned into anopen position, thereby permitting external air to be drawn :into thechimney and avoiding a strong draft through the heat conduits of theboiler which otherwise would operate to cool the water and effeet a lossin heat and waste of fuel.

In the preferred construction a baflie H projects upwardly and forwardlyfrom the inner side of the smoke box and partly across the check passageso as to prevent any air coming into the smoke box through the check boxfrom cooling the water in the boiler and also to prevent the pressure ofthe oil burner and the suction of the chimney from producing a suctioneffect on the check valve which would tend to open the same.

If desired, means may be used in connection with this boiler forsupplying indirectly heated water for domestic and other purposesindependently of the water which is heated directly by the fuel in theboiler. The preferred construction of the means for this purpose shownin Figs. 2, 4 and 6 are constructed as follows:-

The numeral l2 represents a coil of piping having one or more loopswhich are arranged horizontally and transversely in the space within theouter body shell above the depressed rear part 22 of the top of theinner shell and having its opposite ends l3, 74 extending to the outsideof the outer shell. Water admitted to the coil at one end and dischargedat its opposite end will be heated indirectly by the hot water in whichthe coil is submerged and which is contained between the boiler shells.The ends of the coil are supported by a. plate l which closes an opening16 in the respective side wall of the outer shell through which the coilis introduced into the water space of the boiler, this plate beingremovably secured to the outer shell by bolts ll or other suitablemeans. The inner end of the coil is supported in a trough-shaped bracket18 which permits the coil to expand and contract freely in response tovariations in temperature of the water in the boiler. The bracket ismounted on the inner side of a closure plate '19 which covers an opening8!] in the adjacent part of the outer shell and which is detachablysecured to this shell by bolts 6|, as shown in Fig. 4. Upon removing theplates 75 and '19 the indirect water heating coil can be easily removedfrom the boiler for inspection, cleaning and renewal if necessary. Theplates and 19 of the coil '12 and bracket it are identical and may bebolted on either side of the boiler thus permitting the coil to beplaced with its inlet and outlet on the side of the boiler nearest thepiping to which it will be connected. A further advantage derived fromdepressing the rear part 22 of the top of the inner shell is that itprovides a pocket for the reception of the indirect water heating coiland thus permits the latter to be properly submerged without undulyraising the water level or reducing the steam space in the body.

If desired the upper part of the outer shell may be provided with a.pipe 82 for connection with a thermostat, aquastat, vacuum gage or otherinstrument to be used in connection with the boiler.

For the purpose of conserving heat the exterior of the boiler may beprovided with any suitable insulating covering.

I claim as my invention:

1. A boiler comprising a body having an outer shell and an inner shellarranged within the outer shell and forming a front'vertical water legbetween the front parts of these shells, a rear vertical water legbetween the rear parts of these shells, and a. fire box Within the innershell, an outer longitudinal water tube arranged within the fire box andhaving its front and rear ends connected with the front and rear partsof the inner shell and communicating at its opposite ends with the frontand rear water legs, an inner longitudinal fire tube arranged within thewater tube and separated therefrom by an intervening water jacket andhaving its front and rear ends connected with the front and rear partsof the outer shell, a flue arranged below the water tube and fire tubeand extending across the front water leg and connected .at its oppositeends with the front parts of the inner and outer shells, a flame chambercommunicating with said flue and the front end of said fire tube, avertical socket arranged on the inner side of the front part of saidinner shell, and a bafile arranged below the front part of said watertube and across said flue and provided with a tongue engaging said.socket.

2. A boiler comprising a body having an outer shell and an inner shellarranged within the outer shell and forming a front vertical Water legbetween the front parts of these shells, a rear vertical water legbetween the rear parts of these shells, and a fire box within the innershell, a plurality of longitudinal water tubes arranged horizontallyside by side in said fire box and communicating at their opposite endswith said front and rear water legs, a plurality of longitudinal firetubes each arranged in one of said water tubes and connected at itsopposite ends with the front and rear parts of said outer shell, 2. fluearranged below said water tubes and connected with the front parts ofsaid inner and outer shells, a flame chamber communicating with saidflue and said fire tubes, a plurality of vertical sockets arranged onthe inner side of the front part of said inner shell below said flametube, and a baffle having .a rearwardly inclined main part arrangedbelow the front parts of said Water tubes and across the inner end ofsaid flue, a vertical upper part having a plurality of upwardly openingnotches each of which receives the lower part of one of the .watertubes, and attaching tongues projecting downwardly from the lower edge.of the baflie body and each engaging with one of said sockets.

3. A boiler comprising an outer shell having upright longitudinal sidewalls, upright transverse end walls and a top, an inner shell arrangedwithin said outer shell and having upright longitudinal side walls,upright transverse end walls .and a top of which the front part iselevated, the rear part depressed and the intermediate part inclinedrearwardly, water tubes connected at their opposite ends with thetransverse walls of said inner shell, and fire tubes arranged in thewater tubes and connected .at their opposite ends with the transverseend walls of the outer shell.

GEORGE J. LEUVELI NK.

